17 Radiographic Films Single or double emulsion Light sensitivityFilm speedFilm speed is inversely related to exposure needed to produce a given degree of blackness50 speed is half as fast as a 100 speed

18 Radiographic Film Film latitudeRange of exposures which can be used to achieve an acceptable film densityWide range = high latitudeImage contrast suffersNarrow range = low latitudeGood image contrast

27 Beam Limiting DevicesSmaller fields = less scatter and less radiation expsoureCones, cylinders, shuttered collimatorsThey do not shape the beam only exclude the part we don’t want to useLight to illuminate field